Earphone devices like the one according to the preamble of claim 1 are typically used in connection with telecommunication or audio listening. The main requirements to such a device are to ensure a good acoustic coupling with the ear, a secure attachment to the ear and a comfortable wearing.
The prior art discloses several attempts to provide earphone devices seeking to fulfill one or more of these requirements.
EP 1 364 553 B1 discloses an earphone device with a mouthpiece adapted for being inserted into the mouthing of the ear canal and a leaf spring with a varying spring rigidity to abut the conchal wall.
U.S. Pat. No. 6,122,388 discloses an earphone device with a helix protrusion and an ear canal protrusion. The earphone device is secured within the outer ear of the user by the helix protrusion and wall regions that engage the conchal wall and the area of the tragus. The ear canal protrusion does not engage the ear canal wall. A sound channel extends through the ear canal protrusion.
WO 2006/104981 discloses an earphone device according to the preamble of claim 1, wherein a speaker is arranged in the tip of the ear canal protrusion. A disadvantage with this device is that it requires a very small speaker that can be fitted into the tip of the ear canal protrusion.
WO 96/23443 discloses an earphone device according to the preamble of claim 1. A sound bore is provided in the ear canal protrusion. This bore provides means for the sound to travel from the speaker part of the audio communications device to the ear canal of the user. The sound bore is according to the description preferably 0.10 inches (2.54 mm) in diameter. In this way, the sound is lead directly into the ear canal, while the protrusion is preventing surrounding noise from entering the ear canal. A problem with this solution is that the relatively long and narrow sound bore dampens the higher frequencies and thus acts as a high frequency filter. This can make speak harder to understand and reduce the pleasure of music listening.